We celebrate Ullambana on a very large scale having special prayers and making offerings to our ancestors,7 lifes' parents, wandering spirits as well as our debtors.It is locally known as the Hungry Ghosts Festival.

kirtu wrote:Hi WIll! The 15th day of the 7th month on the Tibetan calendar is September 12 this year. In the Japanese tradition it is celebrated in August. When do you have Ullambana Day on your calendar?

Will wrote:August 14 in Chinese tradition. Is that the same day for Japanese?

There's not a single date although there may be an actual official O-Bon (Ullambana Day) date. I just looked it up in Hawaii and it's celebrated from June to late August and that appears to be the case all across the US. Dai Bosatsu Zendo in NY is celebrating O-Bon August 13-14.